1. Field of the Invention
The present invention relates generally to a brake actuating assembly for a vehicle, and more specifically to a clutch assembly within the brake actuating assembly.
2. Discussion of Related Art
Brake actuating assemblies for vehicle parking brakes are manufactured in many different designs, including foot pedal brake actuators and hand brake actuators. A foot pedal brake actuator is typically mounted near the floor of the vehicle and includes a lever having a pedal that is designed to be pushed by the operator's foot in a brake applying direction to set the parking brake. As the lever is moved in the brake applying direction, a clutch ensures that the position of the lever is maintained. In order to disengage the parking brake, the clutch must be released. In some vehicles, a release handle is mounted above the pedal. This handle allows the operator to disengage the parking brake by pulling the release handle, which releases the clutch and allows the pedal to move in a brake releasing direction. Some vehicles that have this type of parking brake actuator also have an automatic parking brake release that includes a vacuum motor or servo that is operatively connected to the clutch. When the vehicle is running and the transmission is shifted into gear, a solenoid valve is actuated. The solenoid valve causes vacuum to be applied to the vacuum motor, which causes the clutch to release the lever, thereby allowing the lever and pedal to move in the brake releasing direction.
Another type of brake actuator is a hand brake actuator that is typically mounted toward the center of the vehicle so that the operator of the vehicle may set and release the brake with one hand. This type of brake actuator typically includes a lever that is pulled upward by the operator to set the parking brake. Many hand brake actuators also include a clutch that allows the position of the lever to be maintained, even when the operator releases the lever. A push button is typically disposed at a distal end of the lever and is pushed by the operator to release the clutch and allow the lever to be moved so that the parking brake may be disengaged.
In both types of brake actuator assemblies, the design of the clutch contributes to the performance of the entire assembly. Because the clutch operates as a torsion lock system, any freewheel backlash that occurs will contribute to a load drop off within the parking brake system. Although the load drop off may be compensated for with a more “robust” design, such a design creates a heavier, more expensive brake actuator assembly.